Many people infected with Zika virus do not get sick. Among those who do develop symptoms, sickness is usually mild, with symptoms that last for several days to a week. Guillain-Barré syndrome (GBS), a rare disorder that can cause muscle weakness and paralysis for a few weeks to several months, is very likely triggered by Zika in a small proportion of infections, much as it is after a variety of other infections. Most people fully recover from GBS, but some have permanent damage.

Sexual transmission of Zika virus from a male partner is also possible.